Screen printing machine



Jan. 8, 1952 R. WADE 2,581,775

SCREEN PRINTING MACHINE Filed Sept. 4, 1948 2 SHEETSSHEET l INVENTOR.

Jan. 8, 1952 Filed Sept. 4. 1948 L;F1 VVAIDE SCREEN PRINTING MACHINE 2SHEETSSHEET 2 HVVENTUR.

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Patented Jan. 8, 1952 UNITED STATES PATENT OFFICE SCREEN. PRINTING.MAGHIN E Louis B. Wade, Los Angeles, Calif.

.-Application September 4, 1948, Serial No. 47,878

4 Claims.

.Myirivention relates to screen .printmg...machines and includedin.theobiects, of .my invenonare:

First to provide a screen printing machine whichincorporates a :novelsqueegee operating mechanism, having a readily adjustable stroke so.that. printing screens. of. different areas may be, interchangeably.used in the machine;

gsecond, to .providea screen printing machine whereinthe,printingscreenisraised and lowered automatically. intime'drelationto themovement of; thesqueegee, the .return movement of the squeegeeoccurring .while the printing screen is raised -so that duringv suchtime. work may be changed;

.Third, to providea screen .printing machine in which the printingscreen, carrier, and the squeegeetoperating.mechanism share a commonpivotal axis so that tilting .movement. of ,the

carriage does notafi'ect operation of the squeegee operating mechanism;and

Fourth, .to.provide a screen printing machine which, althoughautomaticin its operation except for insertionand removalof-the work, is

particularly simpleiof construction-and dependable. in its operation.

With the v above and other objects in -viewas may. appear hereinafterreference-isdirected to the accompanying drawings in which .Eigure .1isasubstantially diagrammatical side view of-my .screen printingmachineshowin it in. aposition assumed when the printing screen israised; I

Figure 2 is. afrontview of .the .machine taken from the planet-2ofFigure l;

:Eigure 3; is a fragmentary -.substantiall-y diagrammaticalqview showing.my screen printing machine inra position assumed when :thescreen iscontact-with the table;

Figure-4-is a fragmentary-view of'the squeegee carriage mechanism shownduring the return movement of the squeegee;

Figure 5 -is a similar view showing. the squeegee duringitsoperatingmovement: and;

Figure disasubstantially diagrammatical view taken' throug-h' 6.-6- ofFigure 1 and illustrating thedrivemeans for the-soreenrprinting machine.

Myscreen printing machine includes a frame structure l of generallyrectangular form which extends under and'wsupports a table! by means ofadjusta-ble posts 3. The'tableis-provided with suitable means. (notshown) for holding work in position for printing. The rear portion. ofthe frame -str'ucture I. includes an A frame 4-which journals-atransversely extended .main shaft: '5.

A pivotal frame structure '01- carrier 6 is mountedon the'main shaft.5'and extends forwardlyover the'tablei. Thecarrier ii'supports ascreenprinting frame 1' which may be con-.- ventional. -Such screen printingframe involves a -wooden inner framecovered by a silk screen on.which-isformed the'design to be printedby rendering-certain .portionsofthis screen permeable-to ink. The inner frame is adjustably mounted invan outer frame for purposes of registering the design. The structure isnotshown in detail inasmuch as the construction of such screen printingframes is well known.

The carrier" 6' also extends rearwardly from-the main-shaft 5 and isprovided with a depending bracketewhich carriesa cam follower 9 adaptedfor-engagement with acam'track II). The cam track may be formed intheside of a main drive gear H. The drive, gear ii is engaged by apinion gear l:2"dri-ven directly by a motor l3 or suitable speedreducing means. A conventional clutch I4 --is interposed with suchclutch being operated' bymeans (not shown) fromthefront of the machine;While the cam and gear .ar rangement is shown forsimplicity.of'illustration, it should be borne in mind that various linkand lever arrangements may be employed to effect oscillation of 'theframe structure or carrierii'.

JOLlIIlQlGd-Oll'thii main shaft 5: is one or more squeegee operatinglevers l5. Each squeegee operating lever includes a radial portion I6and anarcuate portion H. The center of the arcuate portion substantiallycoincides with the forward margin of the printing screen when the partsof the printing machine are inthe position shown in Figure 3. Thearcuate portions of the levers iiare provided with adjustable clamps itwhich arepivota'lly connected tostruts' IS, the forward ends of whichare joined to a squeegee carriage 20 adapted to travelxback and forthacross the screen printing frame. It will thus be seen by examination ofFigureB that irrespective of the adjustment of the clamps N3 the forwardposition of the carriage is-notzaltered. As shown in Figure 1, however,the rearposition of the carriageis altered by adjustment of theclamps-l8. By' this means the length of stroke may be changed asdesired.

The squeegee carriage .22 may be conventional and is illustratedhereinsubstantially diagrammatical; The carriage actuates a squeegee. 2!

the form Ofht bar having a flexible wiping blade adapted to -,engage aprinting screen. for the .ipunposeoh forcing ink through thepermeableportions thereof. It is desirable that a type of squeegee structure beemployed wherein the ink is carried to the forward side of the printingframe without contact with the printing screen inasmuch as the printingscreen is raised from the work during this movement. This may beaccomplished by the use of an ink retainer blade 22 which is positionedfor engagement by the squeegee to form a trough and by pivotallymounting the squeegee so that normally it is urged against the blade 22by springs 23 but is drawn away from the plate when moved across theprinting screen. In addition, elevating means 24 cause the carriage toraise when moved in a direction shown in Figure 4 and to lower when thecarriage is moved in a direction shown in Figure 5.

The squeegee operating levers [5 are connected by lever arms 25 to links26 which, in turn, are joined to levers 21 mounted on the shaft whichcarries the cam Ill and the gear I I.

Operation of my screen printing machine is as follows: The shape of thecam track l and the position of the levers 25 and 21 as well as thesqueegee operating levers l are such that the screen printing frameoccupies a lower position, such as is shown in Figure 3, for apredetermined portion of the cycle and a raised position, such as isshown in Figure 1, during another selected portionof the cycle. printingscreen is in its lower position as shown in Figure 3 the squeegee iscaused to move from the forward toward the rearward side of the screenby rearward pivotal movement of the operating levers l5 about the axisof the main shaft 5. When this stroke is completed the printing screenis raised. During this upward movement or immediately thereafter thesqueegee is moved to its forward position at the same time the operatorremoves the printed material and places new work on the table. By thetime the printing screen is ready to be lowered or during the loweringof the screen the squeegee reaches the forward side thereof ready for aworking stroke.

It will be observed that a particularly simple operating mechanism isprovided and that the desired action of the squeegee carriage isaccomplished by reason of the fact that both the operating levers l5 andthe frame structure 6 pivot about the same axis, namely, the axis of themain shaft 5. It will also be observed that adjustment of the operatingstroke of the squeegee carriage is extremely simple, this beingaccomplished merely by adjustment of the clamps l8, preferably when themachine is in the position shown in Figure 3.

Having fully described my invention, it is to be understood that I donot wish to be limited to the details herein set forth, but my inventionis of the full scope of the appended claims.

I claim:

1. A screen printing machine, comprising: a frame structure; a Worksupporting means thereon; a main shaft supported by said framestructure; a carrier adapted to receive a printing screen andoscillatably mounted on said main shaft above said frame structure .tomove said printing screen between lower printing position and a raisedposition relative to work on said supporting means; a squeegee carriagemovable on said carrier over said printing screen; operating means forsaid carriage including a lever pivoted on the axis of said main shaft,and struts extending from said lever to said carriage; and

During the time that the means for actuating said carrier and saidcarriage in unison whereby an operating stroke of said carriage occurswhen said printing screen is in engagement with said work and a returnmovement occurs when said printing screen is raised from said work.

2. A screen printing machine, comprising: a frame structure, including awork supporting means at the forward portion of said frame structure anda main journal means rearwardly of said work supporting means; aprinting screen carrier pivotally mounted on said main journal means andadapted to move a printing screen between a lower printing position anda raised position; a squeegee carriage mounted on said carrier forforward and rearward movement across said printing screen, said squeegeecarriage including a squeegee element, means coacting with said squeegeeelement to support a quantity of ink, and means for causing saidsqueegee to contact said printing screen and operate thereon duringmovement in one direction and to raise from said screen during movementin the opposite direction; nd a drive means for said carriage includinga lever pivotally mounted on the axis of said main journal means andhaving an arcuate arm and a strut extending therefrom to saidcarriage,,said strut adjustable on said arm to vary the stroke of saidcarriage, the locus of said arcuate arm being in approximate coincidencewith the forward edge of said printing screen when said screen is in itsoperating position and said carriage is in its tion and a raisedposition relative to work on said supporting means; a squeegee carriagemovable over said screen between a forward and a rearward position; anoperating means for said carriage, including a lever pivoted on the axisof said main shaft, said lever having an upright portion, theextremities of which are substantially equidistant from the forwardmargin of said printing screen when said screen is in its lower orprinting position, and struts adjustable on said upright portion andextending to said forward margin for attachment to said carriage; andcoordinated actuating means for said carrier and said operating means tocause rearward movement of said carriage when said printing screen is inits lower or printing position, and to return said carriage when saidprinting screen is in its raised position.

4. A screen printing machine, comprising: a frame structure, including awork supporting means at the forward portion of said frame structure anda main journal means rearwardly of said work supporting means; aprinting screen carrier pivotally mounted on said main journal means andadapted to move a printing screen between a lower printing position andaraised position; a squeegee carriage mounted on said carrier forforward and rearward movement across said printing screenysaid squeegeecarriage including a squeegee element, means co- 7 acting-with saidsqueegee element to support a the opposite direction; and a drive meansfor 5 said carriage including a lever pivotally mounted on the axis ofsaid main journal means and having an upright arm and a strut extendingtherefrom to said carriage, said strut adjustable on said arm to varythe stroke of said carriage, at in extreme points of adjustment saidstrut being approximately equidistant from the forward edge of saidprinting screen when said screen is in its operating position and saidcarriage is in its 6 forward position whereby regardless of the point ofconnection of said strut with said upright arm, the forward position ofsaid carriage remains substantially unchanged.

LOUIS R. WADE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

